Telephone teansmitter



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TELEPHONE TRANSMITTER.

N0. 357,359. Patented Feb. 8, 1887.

W. 0. BA'RNEY.

No. 357,359. Patented Feb. 8,1887.

WILLIAM C. BARNEY, OF NEW YORK, N. Y., A SSIGNOR TO JOSIAH O. REIFF,

OF SAME PLACE.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 357,359, dated February 8, I887. Application filed January 18, 1886. Serial No. 189,813. (No model.)

To all whom it-may concern.-

Be it known that I, WILLIAM CHASE BAR- lNEY, of the city and State of New York, have invented an Improvement in Telephone-Transmitters, ofwhich the followingis a specification.

In my present invention I make use ofintermittent pulsations of electricity in contradistinction to undnlatory currents of electricity for the transmission of sounds.

It is obvious that the variations of theintensity of a continuous current in a closed circuit are confined within a very narrow range,

magnetic force of the magnet of the telephone.

receiver in the circuit are the maximum variations.

In this apparatus two fundamental properties of air are utilized: first, equality of the pressure of air when in motion in all direc- 2 5 tions, and, secondlydncrease of pressure in proportion as the density of the air is increased.

The air-waves, on entering the case through the mouth-piece, do not fall at right angles upon the tympan, and therefore there do not occur rebounds of the air, which materially interfere wit-h following air-waves and prevent the tympan from vibrating in accord with the air waves. In this apparatus the air-waves pass into the case nearly parallel with the tympan, 3 5 and as they reach the narrowest part of the air-chamber the density is greatly increased, and consequently the pressure of the air on the tympan is also greatlyincreased and the tympan is forced against the opposite elec- 40 trode. This contact is severed by the united forces of kinetic energy, of the rebound, and of the pressure of the condensed air. The movement of the tympan begins gradually and increases in force as the density of the air in- 5 creases, and consequently the varying intensity. of the electric current is in proportion to the gradually increasing and decreasing pressure which the tympan makes upon the elec-. trode.

There is always a period during which a current, upon closing a circuit, increases in intensity, as there is a period of decreasing intensity upon opening a circuit. This varying intensity of the electric current produces upon the magnet of the receiving-telephone variations of the magnetic force corresponding faithfully to the varying intensity ofthe electric current.

In the drawings, Figure 1 is a section of my improvedtelephone, representing one of the electrodes at the centerof the tympan and the other electrode in the form of a screw, which is adjustable into proximitywith the electrode on the tympan. Fig. 2 is a similar view with a lever the short arm of which is connected to the center of the tympan and the long arm carries the other electrode. Fig. 3 is a section of my transmitter with one electrode at the end of a pendulum, and Fig.4 is an elevation of the telephone-case.

It is preferable to employ a block of wood,

A, within which is a passage-way, B, having an entrance, M, with a mouthpiece, and an exit, at E, at one side of the case or other convenient place.

My tympan may be of any materials possessing elasticity, either naturally, inherently, or else has it imparted to it by external conditions, such as would be in the case of alimp membranesuch as apiece of bladder-which is strained and held by its edges. I prefer to use mica for the tympan.

The electrodes can be of carbon or metal; but platinum or molybdenum is preferred. One of the electrodesshould be flat, presenting a surface of about one-fourth of an inch in measurement, and the other electrode is preferably rhomboidal. V p

In Figs. 1 and 3 the electrode 0 is fastened to the tympan, and in Fig. 2 the electrode 0 is 0 upon the frame or case. In all instances the other electrode, P, is opposite to, but not in contact with, the electrode 0.

In Fig. 2 the lever L, intervening between the tympan T and the electrodes, increases the 5 movement given to the electrode P on the end of the long arm of the lever by the vibrations of the tympan.

The passage for the air-waves is contracted opposite to the center of the tyinpan, on both sides thereof, so that the air-waves from the mouth-piece are caused to act powerfully upon one side of the tympan, and then such air- "waves, passing around in the passageway B, are condensed against the other side of the iympan by the narrow passage through which it must pass, and then such air-waves pass out thronghihe opening, E.

I claim as my invention 1. The combination, in a telephone-transmitter, of an air-cha1nber having inlet and exit openings and a continuous passage around the tympan, and a tympanlocated therein at other than a right angle to the path of the airwaves, substantially as set forth.

2. The apparatus herein described, consist ing of a,ty1npan situated in an air-chamber and arranged to be acted upon on both sides successively by the same air-waves, and elec trodes or contact'points controlled thereby, substantially as set forth.

3. The combination of a tympau with a case having an air-passage extending around the tympan, so that the airwaves will act first on one side of the tympan and afterward on the opposite side of it, substantially as set forth.

4. The method herein specified of controlling the vibrations of the tympan in a telephonic transmitter, consisting in directing the air-impulses against one side of the tympan and then returning the same, so that such air-impulses act in the opposite direction upon the other side of the said tympan, substantially as specified.

5. The combination, with the tympan and electrodes in a telephonic transmitter, of a case having a return passage-way that concentrates the air-waves first on one side of the tympan and then on the otherside, substantially as set forth.

Signed by me this 9th day of January, A. D. 1886.

XV. O. BARNEY. Witnesses:

G-Eo. T. PINCKNEY, WALLACE L. SERRELL, 

